%I #6 Mar 30 2012 16:48:58
%S 0,1,2,5,16,59,258,1296,7362,46609,325147,2477212,20460278,182076531,
%T 1736623109,17672266151,191111489038,2188592796698,26458831601847,
%U 336735773968857,4500142285227330,63007188219787855,922312862937555109
%N Variation of Boustrophedon transform described in A059219 applied to sequence 0,1,0,0,0,....
%H <a href="/index/Bo#boustrophedon">Index entries for sequences related to boustrophedon transform</a>
%p aaa := proc(m,n) option remember; local i,j,r,s,t1; if m=0 and n=0 then RETURN(0); fi; if m=1 and n=0 then RETURN(1); fi; if n = 0 and m mod 2 = 1 then RETURN(0); fi; if m = 0 and n mod 2 = 0 then RETURN(0); fi; s := m+n; if s mod 2 = 1 then t1 := aaa(m+1,n-1); for j from 0 to n-1 do t1 := t1+aaa(m,j); od: else t1 := aaa(m-1,n+1); for j from 0 to m-1 do t1 := t1+aaa(j,n); od: fi; RETURN(t1); end; # the n-th antidiagonal in the up direction is aaa(n,0), aaa(n-1,1), aaa(n-2,2), ..., aaa(0,n)
%Y Cf. A000667, A059216, A059217, A059220, A059219.
%K nonn
%O 0,3
%A _N. J. A. Sloane_, Jan 20 2001